Help Need in Sequence Diagram

While representing the Login Use Case through Sequence diagram, how can we represent the Alternate flow of signon error/sucess, based on which the NextView would be selected.

Do we need to represent both the cases as different diagrams or it is enough to have a single diagram and give a high-level message like 'GetResponse' instead of Error/Sucess message in which case the representation to the Next View Selected would be generic .